Berrybecker9647
In this work, spiral dextrin/resveratrol (SD/Res) crystal, a new colon-specific drug-delivery system, was established by a novel method of encapsulation and cocrystallization to improve the antidigestion ability compared with the SD/Res inclusion complex (SD/Res IC) prepared by encapsulation and coprecipitation. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that the SD/Res crystal formed a more regular and perfect crystallite than SD/Res IC. Moreover, the encapsulation ability and thermostability of the SD/Res crystal were enhanced as the chain length of SD was increased. In vitro digestion indicated that SD/Res IC merely achieved small intestine-targeted release of resveratrol, while the SD/Res crystal could act as a colon-specific delivery system to protect resveratrol from degradation by gastric acid and pancreatic enzymes. The SD-1/Res crystal presented much higher thermal stability and stronger gastrointestinal stability than other SD/Res crystals and SD/Res ICs, which facilitated its application as a novel colon-target delivery system for resveratrol.A compound K-producing fungus was isolated from meju (fermented soybean brick) and identified as the generally recognized as safe (GRAS) strain Aspergillus tubingensis. The extracellular enzymes obtained after the cultivation of 6 days in the medium with 20 g/L citrus pectin as an inducer showed the highest compound K-producing activity among the inducers tested. Under the optimized conditions of 0.05 mM MgSO4, 55 °C, pH 4.0, 13.4 mM protopanaxadiol (PPD)-type ginsenosides, and 11 mg/mL enzymes, the extracellular enzymes from A. tubingensis completely converted PPD-type ginsenosides in the ginseng extract to 13.4 mM (8.35 mg/mL) compound K after 20 h, with the highest concentration and productivity among the results reported so far. As far as we know, this is the first GRAS enzyme to completely convert all PPD-type ginsenosides to compound K.Three new diterpenoids, boesenmaxanes A-C (1-3), with an unprecedented core skeleton consisting of an unusual C-C bond between C-12 and an exo-cyclic methylene C-13, were isolated from the rhizome extracts of Boesenbergia maxwellii. The structures were elucidated by analysis of spectroscopic and X-ray diffraction data. Electronic circular dichroism spectra were used to determine the absolute configuration. All the isolates were evaluated for their cytotoxic effects, anti-HIV activity, and antimicrobial activity. Boesenmaxanes A and C (1 and 3) showed significant inhibitory activity in the syncytium reduction assay, with EC50 values of 55.2 and 27.5 μM, respectively.The first-order hyperpolarizability of π-conjugated organic molecules is of particular interest for the fabrication of electro-optical modulators. Thus, we investigated the relationship between the molecular structure and the incoherent second-order nonlinear optical response (βHRS) of four salicylidene derivatives (salophen, [Zn(salophen)(OH2)], 3,4-benzophen, [Zn(3,4-benzophen)(OH2)]) dissolved in DMSO. For that, we employed the Hyper-Rayleigh Scattering technique with picosecond pulse trains. Our experimental results pointed out dynamic βHRS values between 32.0 ± 4.8 × 10-30 cm5/esu and 58.5 ± 8.0 × 10-30 cm5/esu at 1064 nm, depending on the molecular geometry of the salicylidene molecules. selleck compound More specifically, the outcomes indicate a considerable increase of βHRS magnitude (∼30%) when in the ligands are incorporated the Zn(II) ion. We ascribed such results to the rise of the planarity of the π-conjugated backbone of the chromophores caused by the Zn(II). Furthermore, we observed an increase of ∼50% in dynamic βHRS when there is a replacement of one hydrogen atom (salophen molecule) by an acetophenone group (3,4-benzophen). This result is related to the increase of the effective π-electron number and the higher charge transfer induced at the excited state. All these findings were interpreted and supported in the light of time-dependent density functional theory (DFT) calculations. Solvent effects were considered in the quantum chemical calculations using the integral equation formalism variant of the polarizable continuum model.Incorporating bismuth, the heaviest element stable to radioactive decay, into new materials enables the creation of emergent properties such as permanent magnetism, superconductivity, and nontrivial topology. Understanding the factors that drive Bi reactivity is critical for the realization of these properties. Using pressure as a tunable synthetic vector, we can access unexplored regions of phase space to foster reactivity between elements that do not react under ambient conditions. Furthermore, combining computational and experimental methods for materials discovery at high-pressures provides broader insight into the thermodynamic landscape than can be achieved through experiment alone, informing our understanding of the dominant chemical factors governing structure formation. Herein, we report our combined computational and experimental exploration of the Mo-Bi system, for which no binary intermetallic structures were previously known. Using the ab initio random structure searching (AIRSS) approach, we identified multiple synthetic targets between 0-50 GPa. High-pressure in situ powder X-ray diffraction experiments performed in diamond anvil cells confirmed that Mo-Bi mixtures exhibit rich chemistry upon the application of pressure, including experimental realization of the computationally predicted CuAl2-type MoBi2 structure at 35.8(5) GPa. Electronic structure and phonon dispersion calculations on MoBi2 revealed a correlation between valence electron count and bonding in high-pressure transition metal-Bi structures as well as identified two dynamically stable ambient pressure polymorphs. Our study demonstrates the power of the combined computational-experimental approach in capturing high-pressure reactivity for efficient materials discovery.Polymer interfaces are key to a range of applications including membranes for chemical separations, hydrophobic coatings, and passivating layers for antifouling. While important, challenges remain in probing the interfacial monolayer where the molecular ordering and orientation can change depending on the chemical makeup or processing conditions. In this work, we leverage surface specific vibrational sum frequency generation (SFG) and the associated dependence on molecular symmetry to elucidate the ordering and orientations of key functional groups for poly(2,2,2-trifluoroethyl methacrylate) bottlebrush polymers and their linear polymer analogues. These measurements were framed by atomistic molecular dynamic simulations to provide a complementary physical picture of the gas-polymer interface. Simulations and SFG measurements show that methacrylate backbones are buried beneath a layer of trifluoroethyl containing side groups that result in structurally similar interfaces regardless of the polymer molecular weight or architecture. The average orientational angles of the trifluoroethyl containing side groups differ depending on polymer linear and bottlebrush architectures, suggesting that the surface groups can reorient via available rotational degrees of freedom. Results show that the surfaces of the bottlebrush and linear polymer samples do not strongly depend on molecular weight or architecture. As such, one cannot rely on increasing the molecular weight or altering the architecture to tune surface properties. This insight into the polymer interfacial structure is expected to advance the design of new material interfaces with tailored chemical/functional properties.In this work, we demonstrate enhancement-mode field-effect transistors by an atomic-layer-deposited (ALD) amorphous In2O3 channel with thickness down to 0.7 nm. Thickness is found to be critical on the materials and electron transport of In2O3. Controllable thickness of In2O3 at atomic scale enables the design of sufficient 2D carrier density in the In2O3 channel integrated with the conventional dielectric. The threshold voltage and channel carrier density are found to be considerably tuned by channel thickness. Such a phenomenon is understood by the trap neutral level (TNL) model, where the Fermi-level tends to align deeply inside the conduction band of In2O3 and can be modulated to the bandgap in atomic layer thin In2O3 due to the quantum confinement effect, which is confirmed by density function theory (DFT) calculation. The demonstration of enhancement-mode amorphous In2O3 transistors suggests In2O3 is a competitive channel material for back-end-of-line (BEOL) compatible transistors and monolithic 3D integration applications.Herbicide safeners enhance herbicide detoxification in crops without reducing their herbicidal efficacy against target weeds. To alleviate maize injury caused by the sulfonylurea herbicide nicosulfuron, a series of 1,3-disubstituted imidazolidine or hexahydropyrimidine derivatives were rationally designed via bioisosterism and active subunit combinations. Thirty novel compounds were synthesized using an efficient one-pot method and low-cost raw materials and characterized by IR, 1H NMR, 13C NMR, and high-resolution mass spectrometer (HRMS). Bioactivity and structure-activity relationship (SAR) were evaluated for herbicide safeners tested against nicosulfuron injury. Most of the compounds effectively protected sensitive maize against nicosulfuron damage. The parent skeletons and substituents of the target compounds both substantially influenced their safener activity. Compound I-3 exhibited superior bioactivity compared to the safener isoxadifen-ethyl. Molecular docking simulations disclosed that compound I-3 competed with nicosulfuron for the acetolactate synthase active site and demonstrated that this is the protective mechanism of safeners. The target compound I-3 presented with strong herbicide safener activity in maize and is, therefore, a potential candidate for the development of a novel herbicide safener.Catalysis by canonical radical S-adenosyl-l-methionine (SAM) enzymes involves electron transfer (ET) from [4Fe-4S]+ to SAM, generating an R3S0 radical that undergoes regioselective homolytic reductive cleavage of the S-C5' bond to generate the 5'-dAdo· radical. However, cryogenic photoinduced S-C bond cleavage has regioselectively yielded either 5'-dAdo· or ·CH3, and indeed, each of the three SAM S-C bonds can be regioselectively cleaved in an RS enzyme. This diversity highlights a longstanding central question what controls regioselective homolytic S-C bond cleavage upon SAM reduction? We here provide an unexpected answer, founded on our observation that photoinduced S-C bond cleavage in multiple canonical RS enzymes reveals two enzyme classes in one, photolysis forms 5'-dAdo·, and in another it forms ·CH3. The identity of the cleaved S-C bond correlates with SAM ribose conformation but not with positioning and orientation of the sulfonium center relative to the [4Fe-4S] cluster. We have recognized the reduced-SAM R3S0 radical is a (2E) state with its antibonding unpaired electron in an orbital doublet, which renders R3S0 Jahn-Teller (JT)-active and therefore subject to vibronically induced distortion. Active-site forces induce a JT distortion that localizes the odd electron in a single priority S-C antibond, which undergoes regioselective cleavage. In photolytic cleavage those forces act through control of the ribose conformation and are transmitted to the sulfur via the S-C5' bond, but during catalysis thermally induced conformational changes that enable ET from a cluster iron generate dominant additional forces that specifically select S-C5' for cleavage. This motion also can explain how 5'-dAdo· subsequently forms the organometallic intermediate Ω.